1. Field of the Invention
This invention relates generally to well cleaning or opening methods and apparatus, and is more particularly concerned with a combination surging and jetting method and apparatus.
2. Discussion of the Prior Art
It is common for wells of various types to become clogged, so cleaning is necessary for the well to continue to function. Also, when wells are first drilled, the surrounding area may be naturally clogged enough to retard or prevent fluid flow. Sometimes the clog in the well is due to corrosion, accumulation of inorganic materials or the like, and sometimes the clog in the well is due to growth of bacterial colonies. The latter is discussed in more detail in U.S. Pat. No. 4,765,410, and that disclosure is incorporated herein by this reference.
The method disclosed in the above mentioned patent utilizes a jet for some cleaning of the well screen and of the interior of the well casing, then relies on a circulation of heated solution, and perhaps some pressure, for thorough cleaning of the well screen and the gravel pack.
Another common technique for use in cleaning wells is surging, in which a surge block substantially fills the well casing, and is reciprocated within the well casing to cause a reciprocating fluid flow. This fluid flow assists in breaking loose clogging material, and can force chemicals used out into the aquifer.
When both jetting and surging are to be used on the same well, one tool has been inserted and used, then that tool removed from the well and the other tool inserted into the well for use. Repetitions of the treatments required repetitions of the removal and re-insertion which requires much time and labor.